#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<stddef.h>
#define OFFSETOF(name,member)  (size_t)&(((name *)0)->member)
struct Str
{
	int a;
	char b;
	float c;
};
int main()
{
	struct Str S = { 0 };
	printf("%zd\n", offsetof(struct Str, b));
	printf("%zd\n", OFFSETOF(struct Str, b));
	return 0;
}